US11126805B2 - Method for adjusting phase in contactless communication - Google Patents

Method for adjusting phase in contactless communication Download PDF

Info

Publication number
US11126805B2
US11126805B2 US16/374,837 US201916374837A US11126805B2 US 11126805 B2 US11126805 B2 US 11126805B2 US 201916374837 A US201916374837 A US 201916374837A US 11126805 B2 US11126805 B2 US 11126805B2
Authority
US
United States
Prior art keywords
signal
controller
reader
indication
received
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active, expires
Application number
US16/374,837
Other languages
English (en)
Other versions
US20190325177A1 (en
Inventor
Anthony TORNAMBE
Nicolas CORDIER
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STMicroelectronics Rousset SAS
Original Assignee
STMicroelectronics Rousset SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by STMicroelectronics Rousset SAS filed Critical STMicroelectronics Rousset SAS
Assigned to STMICROELECTRONICS (ROUSSET) SAS reassignment STMICROELECTRONICS (ROUSSET) SAS ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: Cordier, Nicolas, TORNAMBE, Anthony
Publication of US20190325177A1 publication Critical patent/US20190325177A1/en
Application granted granted Critical
Publication of US11126805B2 publication Critical patent/US11126805B2/en
Active legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
    • G06K7/10366—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves the interrogation device being adapted for miscellaneous applications
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
    • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
    • G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
    • G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
    • G06K19/0723—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/0095—Testing the sensing arrangement, e.g. testing if a magnetic card reader, bar code reader, RFID interrogator or smart card reader functions properly
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
    • G06K7/10237—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves the reader and the record carrier being capable of selectively switching between reader and record carrier appearance, e.g. in near field communication [NFC] devices where the NFC device may function as an RFID reader or as an RFID tag
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
    • G06K7/10316—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves using at least one antenna particularly designed for interrogating the wireless record carriers
    • H04B5/0062—
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
    • H04B5/70—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes
    • H04B5/72—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes for local intradevice communication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
    • H04B5/70—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes
    • H04B5/77—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes for interrogation

Definitions

  • Implementations and embodiments of the invention relate a method for adjusting phase in contactless communications.
  • NFC Near field communication
  • the NFC technology is particularly suitable for connecting any type of user device and allows fast and easy communications.
  • a contactless object is an object capable of exchanging information, via an antenna, with another contactless object, for example a reader, according to a contactless communication protocol.
  • An NFC object which is a contactless object, is an object compatible with the NFC technology.
  • the NFC technology is an open technological platform standardized in the ISO/IEC 18092 and ISO/IEC 21481 standards but incorporates numerous already existing standards, such as for example the type A and type B protocols defined in the ISO-14443 standard, which can be communication protocols usable in the NFC technology.
  • a cellular mobile telephone can be used (if it is equipped with specific circuitry) for exchanging information with another contactless device, for example, a contactless reader, by using a contactless communication protocol usable in the NFC technology.
  • the reader During a transmission of information between a reader and an object emulated in tag or card mode, the reader generates a magnetic field by means of its antenna which is generally, within the conventionally used standards, a sinusoidal wave at 13.56 MHz.
  • the strength of the magnetic field is between 0.5 and 7.5 amps/meter RMS (RMS standing for “Root Mean Square” in English).
  • the antenna of the object emulating the tag or the card modulates the field generated by the reader. This modulation is carried out by modifying the load connected to the terminals of the antenna of the object.
  • the output impedance of the antenna of the reader changes because of the magnetic coupling between the two antennas. This results in a change in the amplitudes and/or the phases of the voltages and currents present at the level of the antennas of the reader and of the object.
  • the information to be transmitted from the object to the reader is transmitted by modulation of load on the currents of the reader's antenna.
  • the load variation carried out during the load modulation results in an amplitude and/or phase modulation of the signal (voltage or current) at the level of the antenna of the reader.
  • a copy of the antenna current is generated and injected into the reception chain of the reader where this current is demodulated and processed in order to extract the transmitted information.
  • the reader and the object emulated in card mode both generate an electromagnetic field.
  • this operating mode is used when the object is provided with its own power source, for example a battery, as is the case in a cellular mobile telephone which is then emulated in card mode.
  • Each of the NFC devices transmits the data using a modulation scheme, typically an amplitude modulation scheme of the ASK (Amplitude Shift Keying) type.
  • ASK Amplitude Shift Keying
  • the signal transmitted by the device emulated in card mode is in phase or in phase opposition with the signal received by the reader in order to have the highest possible amplitude of modulation in absolute value at the level of the reader and therefore also at the level of the device emulated in card mode.
  • a phase adjustment is generally carried out at the level of the device emulated in card mode during the development of the device in a known environment and with a well-adjusted impedance matching circuit.
  • the matching is not the optimum matching resulting in a dispersion of the performances of the device in card mode.
  • Implementations and embodiments of the invention relate to wireless communication between a reader and an object, for example but not in a limiting manner, a mobile telephone emulated in card mode, in particular an NFC (Near Field Communication) object, and more particularly the compensation of a phase shift between the signal transmitted by the object and the one received by the reader during a communication by active load modulation (ALM standing for “Active Load Modulation”).
  • ALM Active Load Modulation
  • Embodiments of the invention provide a method to reduce by a maximum amount or even to eliminate the phase shift.
  • an object capable of being emulated in card mode, for example a telephone, a tablet, a smart watch, these examples not being limiting.
  • the object is configured for, at the end of assembly and production, carrying out an auto-adjustment of a phase shift peculiar to that object, on the basis for example of a measurement of the level of the signal received on the input terminals of the controller, for example, an NFC controller, of the object after a transmission of a non-modulated signal by that object set in reader mode, and of a correspondence table, stored in a memory of that object and resulting from adjustments carried out on a reference object exhibiting in particular an optimum matching.
  • this auto-adjustment is advantageously carried out at the end of production and assembly, without necessitating the presence of a reader, and once and for all without it being necessary subsequently to repeat such an adjustment, in particular during subsequent communications between the object and the reader.
  • This method comprises production of a reference object structurally and functionally analogous to the object and comprising a reference resonant circuit tuned to a reference resonant frequency, for example 13.56 MHz. Determinations, for different frequencies within a range of frequencies about the reference resonant frequency, of reference phase shifts within the reference object make it possible to obtain resultant phase shifts that are zero or equal to pi to within a tolerance, between a signal transmitted by the reference antenna of the reference object to a test reader, for example, a reader of a certification bench defined in the EMVCo standard, and a signal received from the test reader at the level of the reference antenna.
  • a test reader for example, a reader of a certification bench defined in the EMVCo standard
  • the amplitude of the modulation can be positive or negative depending on whether the signal transmitted by the antenna and the signal received from the test reader are in phase opposition or in phase.
  • obtaining resultant phase shifts that are equal to or close to 0 or to pi is equivalent to obtaining positive modulation amplitudes higher than a threshold and preferably as high as possible.
  • the threshold can for example be equal to 95% of the maximum possible positive amplitude of modulation.
  • the method according to this aspect also comprises a production of the object (a production of the object) including a storage in a memory of the object of at least one indication linking these reference phase shifts with reference characteristics obtained on the basis of signals uniquely transmitted by the reference object.
  • the method according to this aspect therefore also comprises, after the object has been produced, an auto-adjustment by the object of the phase shift within that object on the basis of the at least one stored indication and of at least one characteristic obtained on the basis of a signal uniquely transmitted by the object, the at least one characteristic being of the same type as the reference characteristics.
  • this characteristic can be a signal level received at the input of the controller, or it can be the phase of the transmitted signal or again the consumption during the transmission.
  • a reference object is produced of which the matching circuit and the antenna have restive, capacitive and inductive values precisely adjusted in such a way as to exhibit a reference resonant frequency, typically a frequency of 13.56 MHz in the case of type A or B protocols of the ISO-14443 standard and for this reference object there are determined reference phase shifts corresponding to different values of the frequency about the reference frequency.
  • a reference resonant frequency typically a frequency of 13.56 MHz in the case of type A or B protocols of the ISO-14443 standard and for this reference object there are determined reference phase shifts corresponding to different values of the frequency about the reference frequency.
  • the object is made to transmit a signal, in the absence of a reader, and the measurement of at least one characteristic obtained on the basis of that signal combined with a stored indication, for example a correspondence table or law, makes it possible to adjust the object's own phase shift which will make it possible to obtain, during subsequent operational communications with a reader, a limited phase shift between the signal transmitted by the object and the signal received from the reader.
  • this adjustment of the object's own phase shift notably does not necessitate either the knowledge of the resonant frequency of the resonant circuit of the object or the knowledge of the real values of the components of the impedance matching circuit.
  • the reference object comprises a reference controller connected to a reference antenna by the intermediary of a reference impedance matching circuit and together forming the reference resonant circuit.
  • the reference phase shifts are advantageously phase shifts between signals transmitted at the output of the reference controller and signals received at the input of the reference controller.
  • the reference controller 's phase shifts which are intended for compensating for the phase shifts due to the components of the transmission path and those due to the components of the reception path of the reference object.
  • phase shifts of the object's controller which are also intended for compensating for the phase shifts due to the components of the transmission path and those due to the components of the reception path of that object.
  • the reference characteristics comprise reference levels of received signals resulting from the signals uniquely transmitted by the reference object and the at least one characteristic comprises a level of a received signal resulting from the signal uniquely transmitted by the object.
  • the reference levels of the received signals are, for example, the reference levels of signals received at the input of the reference controller and the level of a received signal resulting from the signal uniquely transmitted by the object is for example the level of the signal received at the input of the object's controller.
  • Both the reference object and the produced object are advantageously capable of operating in reader mode or in card mode.
  • the determinations of the reference phase shifts can comprise a setting of the reference object in its card mode and, for each frequency of the range of frequencies, a transmission by the test reader of a test signal, for example, a command conforming with the protocol used, a reception by the test reader of the response signal transmitted by the reference object, and an adjustment of the reference phase shift in the reference object in order to obtain at the level of the test reader an amplitude of modulation higher in absolute value than a threshold, for example equal to 95% of the maximum positive amplitude of modulation.
  • the determinations of the reference phase shifts can also comprise a setting of the reference object in its reader mode and, for each frequency of the range of frequencies, a transmission by the reference object of a non-modulated signal having the frequency and a determination of the reference level of the signal received by the reference controller because of that transmission, and an elaboration of a relationship of correspondence between the different values of reference levels of the of the received signals and the corresponding values of reference phase shifts, the stored indication being representative of the relationship.
  • the indication can comprise a table of correspondence between the different values of reference levels of the received signals and the corresponding values of reference phase shifts.
  • the relationship is a straight line.
  • the indication can comprise values making it possible to characterize the straight line, such as for example the slope and one point of the straight line, or two points on the straight line.
  • the auto-adjustment by the object can comprise a setting of the object in reader mode, a transmission by the object of a non-modulated signal at the frequency of the resonant circuit of the object, a determination of the level of the signal received by the object's controller, and an adjustment of the phase shift on the basis of the level and of the stored indication.
  • the object comprises a controller connected to an antenna by the intermediary of an impedance matching circuit and together forming a resonant circuit having a resonant frequency.
  • a signal transmitted by the antenna of the object stems from an initial signal generated within the controller, and the auto-adjustment of the phase shift then comprises for example an adjustment of a delay on the initial signal.
  • the object can for example be a communication device, such as a mobile telephone or a tablet.
  • an object capable of contactless communication with a reader by active charge modulation comprising a controller connected to an antenna by the intermediary of an impedance matching circuit and together forming a resonant circuit having a resonant frequency, a memory containing an indication resulting from the application of the method defined above, the controller being configured for carrying out an auto-adjustment of that object's phase shift in accordance with the method defined above.
  • an object capable of contactless communication with a reader by active load modulation, the object comprising a controller connected to an antenna by the intermediary of an impedance matching circuit and together forming a resonant circuit having a resonant frequency, the controller being configured for making the object transmit, in the absence of a signal received from a reader, a signal at the frequency of the resonant circuit of the object, determining at least one characteristic obtained from the signal uniquely transmitted by the object, and carrying out an adjustment of a phase shift within the object on the basis of the at least one characteristic and of an indication stored in a memory of the object and linking values of phase shifts with values of the at least one characteristic.
  • the phase shift is a phase shift between a signal transmitted at the output of the controller and a signal received at the input of the controller.
  • the at least one characteristic comprises the level of the signal received at the input of the controller resulting from the signal uniquely transmitted by the object.
  • the controller is configured for, in one embodiment, setting the object in reader mode, making the object transmit a non-modulated signal at the frequency of the resonant circuit of the object, determining the level of the signal received at the input of the controller of the object, and carrying out an adjustment of the phase shift between the transmitted signal and the signal received on the basis of the level of the received signal and of the stored indication.
  • the indication can comprise a table of correspondence between different values of levels of received signals and corresponding values representative of the phase shifts.
  • the indication can comprise values making it possible to characterize a straight line representative of the evolution of the values of phase shifts as a function of values of levels of received signals.
  • the controller comprises an adjustable delay element disposed in the transmission path of the signals and a circuit for adjusting the value of the delay in such a way as to obtain the desired phase shift.
  • the controller is for example a controller compatible with a near field communication (NFC) technology.
  • NFC near field communication
  • the object can thus be a communication device, such as a mobile telephone or a tablet, or furthermore a smart watch, without these examples being limiting.
  • FIGS. 1 to 10 show different implementations and embodiments of the invention.
  • the reference APP denotes an object, in this case a communication device, for example a cellular mobile telephone, equipped with an antenna ANT 1 for establishing telephone communications.
  • a communication device for example a cellular mobile telephone, equipped with an antenna ANT 1 for establishing telephone communications.
  • the device APP also comprises a conventional NFC system comprising a contactless component CMP of the NFC type, for example an NFC controller or microcontroller.
  • the device is capable of contactless communication with a reader by active load modulation.
  • the microcontroller CMP conventionally has two contacts TX 1 , TX 2 usable in reader mode and two other contacts RX 1 , RX 2 usable in reader mode and in card mode.
  • the component CMP can be equipped with an internal switch SWI making it possible to short-circuit the terminals TX 1 and TX 2 for operation in card mode or not to short-circuit the terminals TX 1 and TX 2 in order to authorize operation in reader mode.
  • An antenna ANT 2 for example an inductive winding, is usable for contactless communication with an external device.
  • a first terminal B 1 of this antenna ANT 2 is connected to the contacts TX 1 and RX 1 whereas the second terminal B 2 of the antenna ANT 2 is connected to the contacts TX 2 and RX 2 .
  • an external impedance matching circuit 1 is connected between the antenna ANT 2 and the component CMP.
  • this impedance matching circuit can comprise a filter FL intended to filter out electromagnetic interference (EMI filter).
  • EMI filter electromagnetic interference
  • This filter FL is conventionally a filter of the LC type in this case comprising a coil B 11 connected in series between the contact TX 1 and ground GND, with a capacitor C 11 .
  • the filter FL also comprises a coil B 12 connected in series between the contact TX 2 and ground GND, with a capacitor C 12 .
  • the inductance of the coil B 11 and of the coil B 12 is equal to LEMI whilst the capacitive value of the capacitors C 11 and C 12 is equal to CEMI.
  • reference cut-off frequency for example 20 MHz for a carrier frequency of 13.56 MHz.
  • these reference values LEMI and CEMI are chosen so as to form a resonant circuit in the vicinity of the reference cut-off frequency f of the filter FL.
  • the impedance matching circuit also comprises the capacitors C 1 , C 2 , CS 1 and CS 2 .
  • the capacitors C 1 and C 2 form a capacitive divider at the terminals of the contacts RX 1 and RX 2 .
  • capacitors CS 1 and CS 2 are chosen in such a way as to maximize the current in the antenna ANT 2 in order to increase the amplitude of the electromagnetic field.
  • the component CMP forms, with the antenna ANT 2 and the external impedance matching circuit, a resonant circuit having a resonant frequency equal to the carrier frequency, for example 13.56 MHz in the case of a type A or type B communication protocol defined in the ISO/IEC 14443 standard.
  • the real inductances and the real capacitive values of the different elements of this external impedance matching circuit can vary with respect to the theoretical values notably because of the technological spread of the coils and capacitors used.
  • the reader transmits a signal SGR which exhibits a phase ⁇ r.
  • phase shift equal to ⁇ alm - ⁇ r between the signal transmitted by the object and the signal received from the reader.
  • phase shift ⁇ t is due to the components (resistors, capacitors, inductances) of the transmission path whilst the phase shift ⁇ r is due to the components (resistors, capacitors, inductances) of the reception path.
  • ⁇ r and ⁇ t vary from one communication device to another because of the tolerances of the components and of the antenna ANT 2 .
  • the tolerances of the antenna depend on the mechanical tolerances of the antenna and also on the mechanical tolerances of the assembly because of the presence of metal parts in the proximity of the antenna.
  • ⁇ c is a configurable parameter in the component CMP stored in memory.
  • phase variations induced by these tolerances can be as much as 120 degrees, that is to say plus or minus 60 degrees for the phase ⁇ alm .
  • the amplitude LMA of the charge modulation generated by a device APP shifted by 60 degrees is reduced to half of the maximum value obtained with a well-adjusted device and this gives rise to interoperability problems with certain readers.
  • the infrastructure of contactless readers is not frequently renewed, particularly in the public transport field and the communication device must operate with old readers with limited performance (simple envelope detection reception architecture unlike architectures having two channels I and Q in phase quadrature).
  • an auto-adjustment phase at the end of production, or calibration phase aimed at determining the phase compensation ⁇ c for each device APP produced in such a way as to bring back the phase variation ⁇ alm for example to plus or minus 15 degrees over the whole of the production.
  • this auto-adjustment makes it possible to determine ⁇ c without the use of a test reader.
  • the error ⁇ c via a law or a table so as to compensate for the variations in ⁇ r and ⁇ t in order to keep the phase of the signal ⁇ alm within a limited phase range.
  • the reference object or device is a device that is structurally and functionally analogous to the device APP produced but in particular having an impedance matching circuit and an antenna produced with components, the values of which are perfectly controlled, which makes it possible to have for the resonant circuit formed and the matching circuit, a reference resonant frequency typically equal to the frequency of the carrier, for example 13.56 MHz.
  • FIGS. 3 to 6 are now referred to more particularly in order to illustrate a non-limiting example of implementation of the method according to the invention relating more particularly to the elaboration of the law or of the table which will be stored in the memory of the object for the purpose of its self-testing or auto-adjustment.
  • the characteristic of the transmitted signal which will be taken into account is the level of the signal received at the input of the controller and resulting from the transmission of the signal at the level of the antenna, when the object is set in reader mode.
  • a step 300 there is produced the reference object or device APPR comprising a reference controller CMPR, a reference impedance matching circuit 1 R and a reference antenna ANT 2 R.
  • the reference object is set into reader mode (step 301 ).
  • the reference object is made to transmit a non-modulated signal.
  • this non-modulated signal (step 302 ) is transmitted at the level of the antenna of the reference device, the latter will capture a received signal level which will be measured (step 303 ) at the input terminals RX 1 , RX 2 of the component CMP (NFC controller) of the reference object.
  • a level NVRi of signal received at the input of the component CMP is thus obtained, this level NVRi being associated with the frequency Fi.
  • the purpose of another operation is to determine, for each frequency Fi, the phase shift DPHRi (corresponding to the compensation ⁇ c ) suitable for the reference controller, in such a way as to obtain an amplitude of modulation LMA greater than a threshold, typically the highest possible in absolute value.
  • steps ( 304 ) to ( 308 ) in FIG. 3 can be carried out before or after steps ( 301 ) to ( 303 ) as shown in FIG. 10 , for example.
  • the reference object or device is set in card mode (step 304 ).
  • test reader RDT for example a test reader of an EMVCo test bench, is made to send a command (step 305 ).
  • the reference object As the reference object is in card mode, it will respond to this request by sending a response (step 306 ).
  • the command has a phase shift with respect to the response.
  • the amplitude of modulation LMA is then measured at the level of the reader of the test bench.
  • the amplitude of modulation LMA corresponds to the voltage difference with respect to the level of the field generated by the test reader.
  • phase shift DPHRi is then adjusted in the reference device in such a way as to obtain a level of amplitude LMA, for example a positive level, greater than a threshold.
  • This threshold can for example be equal to 95% of the maximum.
  • Steps ( 305 ) to ( 308 ) are repeated for all of the frequencies Fi of the range of frequencies and there is then obtained, as illustrated in FIG. 7 , a set of reference phase shifts DPHRi respectively associated with the different frequencies Fi.
  • the correspondence relationship LCR can then for example be approximated by a straight line DR.
  • This indication IND ( FIG. 3 ) can be a correspondence table comprising all of the pairs of points DPHRi, NVRi respectively corresponding to the frequencies Fi.
  • FIG. 9 describes in particular the auto-adjustment or self-test phase of a product having been produced on a production line.
  • step ( 90 ) which represents the production steps in an overall manner, comprising in particular the assembly of the different components, there is stored in a memory MM of the object APP, the indication obtained at the end of steps ( 303 ) and ( 308 ).
  • a device APP comprising the indication in its memory MM, for example the correspondence table LKT (Look-up table).
  • the device APP is then set in reader mode (step 901 ) and the device APP is made to transmit a non-modulated signal (step 902 ).
  • the device has therefore been calibrated and this has been done without it being necessary to use any reader whatsoever or any signal whatsoever coming from a reader.
  • the measurement of a characteristic obtained solely from the signal transmitted by the object makes it possible, with the indication stored in memory, to carry out the phase shift adjustment.
  • this characteristic has been descried as being a signal level received at the input of the controller, other characteristics are possible, such as for example the phase of the transmitted signal, or the consumption during the transmission.
  • this calibration is carried out just once, which dispenses with the need to repeat it during each subsequent communication with a reader.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Theoretical Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Artificial Intelligence (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Health & Medical Sciences (AREA)
  • Electromagnetism (AREA)
  • Signal Processing (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Near-Field Transmission Systems (AREA)
US16/374,837 2018-04-24 2019-04-04 Method for adjusting phase in contactless communication Active 2039-04-21 US11126805B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1853557A FR3080476A1 (fr) 2018-04-24 2018-04-24 Procede de reglage de la phase du signal emis par un objet capable de communiquer sans contact avec un lecteur par modulation active de charge, et objet correspondant
FR1853557 2018-04-24

Publications (2)

Publication Number Publication Date
US20190325177A1 US20190325177A1 (en) 2019-10-24
US11126805B2 true US11126805B2 (en) 2021-09-21

Family

ID=63294339

Family Applications (1)

Application Number Title Priority Date Filing Date
US16/374,837 Active 2039-04-21 US11126805B2 (en) 2018-04-24 2019-04-04 Method for adjusting phase in contactless communication

Country Status (4)

Country Link
US (1) US11126805B2 (de)
EP (1) EP3561730B1 (de)
CN (2) CN210222766U (de)
FR (1) FR3080476A1 (de)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4002707A1 (de) 2020-11-24 2022-05-25 Nxp B.V. Phasenwertbestimmung für eine vorrichtung zur emulation einer nfc-karte mit verwendung von aktiver lastmodulation
CN114650079A (zh) * 2020-12-17 2022-06-21 意法半导体有限公司 非接触通信的反向调制方法，以及相应的应答器
EP4106211A1 (de) * 2021-06-15 2022-12-21 Nxp B.V. Rfid-sendeempfänger mit implementierter phasenkalibrierung und phasenkalibrierungsverfahren
CN115001542B (zh) * 2022-07-28 2022-11-08 深圳市汇顶科技股份有限公司 近场通信的方法和近场通信设备
CN115378569B (zh) * 2022-10-24 2023-01-06 北京紫光青藤微系统有限公司 用于调整相位的方法、装置、电子设备及存储介质
CN115664626B (zh) * 2022-12-13 2023-05-12 紫光同芯微电子有限公司 时钟相位确定方法及装置、近场通信芯片和近场通信设备

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070296593A1 (en) * 2006-06-27 2007-12-27 Hall Stewart E Resonant circuit tuning system with dynamic impedance matching
US7671720B1 (en) 2004-09-01 2010-03-02 Alien Technology Corporation Method and appratus for removing distortion in radio frequency signals
EP2431925A1 (de) 2010-09-21 2012-03-21 Inside Secure Verfahren und Vorrichtung für aktive Lastmodulation durch induktive Kopplung
EP2500840A1 (de) 2011-03-15 2012-09-19 Commissariat à l'Énergie Atomique et aux Énergies Alternatives Datenübertragungssystem und entsprechende Verwaltungsmethode
US20140038662A1 (en) * 2012-03-26 2014-02-06 Motorola Mobility Llc Method and apparatus for compensating for phase shift in a communication device
US20160197718A1 (en) 2013-09-13 2016-07-07 Inside Secure Method and device for transmitting data by inductive coupling with controlled self-oscillation
EP3276986A1 (de) 2016-07-27 2018-01-31 Stmicroelectronics Sa Kontaktloses kommunikationsverfahren zwischen einem objekt, beispielsweise einem im kartenmodus emulierten mobiltelefon, und einem lesegerät durch aktive lastmodulation
US20180034510A1 (en) * 2016-08-01 2018-02-01 Nxp B.V. Method and system to measure the phase offset based on the frequency response in a nfc system
US20180070198A1 (en) * 2016-09-08 2018-03-08 Samsung Electronics Co., Ltd. Near field communication device

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3026583A1 (fr) * 2014-09-29 2016-04-01 St Microelectronics Int Nv Procede de gestion du fonctionnement d'un objet capable de communiquer sans contact avec un lecteur, dispositif et objet correspondants
JP6593349B2 (ja) * 2015-02-10 2019-10-23 ソニー株式会社 受信装置および通信システム

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7671720B1 (en) 2004-09-01 2010-03-02 Alien Technology Corporation Method and appratus for removing distortion in radio frequency signals
US20070296593A1 (en) * 2006-06-27 2007-12-27 Hall Stewart E Resonant circuit tuning system with dynamic impedance matching
EP2431925A1 (de) 2010-09-21 2012-03-21 Inside Secure Verfahren und Vorrichtung für aktive Lastmodulation durch induktive Kopplung
US20120071089A1 (en) 2010-09-21 2012-03-22 Inside Secure Method and Device for Active Load Modulation by Inductive Coupling
EP2500840A1 (de) 2011-03-15 2012-09-19 Commissariat à l'Énergie Atomique et aux Énergies Alternatives Datenübertragungssystem und entsprechende Verwaltungsmethode
US20120238899A1 (en) * 2011-03-15 2012-09-20 Commissariat A L'energie Atomique Et Aux Energies Alternatives Data transfer system and associated management method
US20140038662A1 (en) * 2012-03-26 2014-02-06 Motorola Mobility Llc Method and apparatus for compensating for phase shift in a communication device
US20160197718A1 (en) 2013-09-13 2016-07-07 Inside Secure Method and device for transmitting data by inductive coupling with controlled self-oscillation
EP3244351A1 (de) 2013-09-13 2017-11-15 Inside Secure Verfahren und vorrichtung zur datenübertragung mittels induktiver kopplung mit gesteuerter selbstoszillation
EP3276986A1 (de) 2016-07-27 2018-01-31 Stmicroelectronics Sa Kontaktloses kommunikationsverfahren zwischen einem objekt, beispielsweise einem im kartenmodus emulierten mobiltelefon, und einem lesegerät durch aktive lastmodulation
US20180034505A1 (en) 2016-07-27 2018-02-01 Stmicroelectronics Sa Method of contactless communication between an object and a reader by active load modulation
US20180034510A1 (en) * 2016-08-01 2018-02-01 Nxp B.V. Method and system to measure the phase offset based on the frequency response in a nfc system
EP3280064A1 (de) 2016-08-01 2018-02-07 Nxp B.V. Verfahren und system zur messung des phasenversatzes auf basis des frequenzgangs in einem nfc-system
US20180070198A1 (en) * 2016-09-08 2018-03-08 Samsung Electronics Co., Ltd. Near field communication device

Also Published As

Publication number Publication date
CN110399755A (zh) 2019-11-01
EP3561730B1 (de) 2022-06-01
FR3080476A1 (fr) 2019-10-25
EP3561730A1 (de) 2019-10-30
US20190325177A1 (en) 2019-10-24
CN210222766U (zh) 2020-03-31
CN110399755B (zh) 2023-12-29

Similar Documents

Publication Publication Date Title
US11126805B2 (en) Method for adjusting phase in contactless communication
JP6967385B2 (ja) Ｎｆｃシステムにおいて周波数応答に基づき位相オフセットを測定する方法及びシステム
US11361209B2 (en) Power electronics for use in smart cards and other applications
US9515750B2 (en) Systems and methods for self-calibration for wireless communication
CN107682292B (zh) Nfc系统中有源负载调制的相位的高分辨率调谐方法和系统
EP3280062A1 (de) Verfahren und system zum betreiben einer vorrichtung zur kommunikation mittels induktiver kopplung
US11403502B2 (en) Method for managing the operation of an object that is able to contactlessly communicate with a reader
EP3451546B1 (de) Treiberschaltung für nfc-antenne
US10686495B2 (en) Frequency adjustment of an NFC circuit
CN109560837B (zh) 用于操作通过电感耦合通信的通信装置的方法和系统
US11544480B2 (en) Method for compensating for a phase shift between the signal emitted by an object and that received from a reader equipped with an envelope detector and corresponding object
Dieng et al. Study of adaptive tuning strategies for near field communication (nfc) transmitter module
JP2019068166A (ja) Ｒｆｉｄリーダライタ装置、インピーダンス調整方法、プログラム
EP4106211A1 (de) Rfid-sendeempfänger mit implementierter phasenkalibrierung und phasenkalibrierungsverfahren
WO2022243173A1 (en) Transmitter with a frequency measurement stage

Legal Events

Date Code Title Description
AS Assignment

Owner name: STMICROELECTRONICS (ROUSSET) SAS, FRANCE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:TORNAMBE, ANTHONY;CORDIER, NICOLAS;REEL/FRAME:048790/0600

Effective date: 20180912

FEPP Fee payment procedure

Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS

STCF Information on status: patent grant

Free format text: PATENTED CASE